Spreading out of the hands was a common posture for prayer in the Bible (1 Kings 8:22; Psalm 88:9; Isaiah 1:15; 1 Timothy 2:8). Solomon assumed this same position when he offered his prayer of dedication for the temple (1 Kings 8:54; 2 Chronicles 6:13).
5 And at the evening sacrifice I rose from my fasting, with my garment and my cloak torn, and fell upon my knees and spread out my hands to the LORD my God,